More than half of Oakland high school students receive no sex education, according to a new study.

And the lack of instruction on contraceptives, sexual health, and basic reproductive facts may be contributing to absenteeism -- as well as Oakland's "dubious honor of having the highest chlamydia rates in Alameda County," the East Bay Express reported.

A full 62 percent of students in a 2012 study said that they had spent "no time on sex education," the newspaper reported. Worse, others reported that the only place they received any instruction on the subject was school.

The lack of a sex curriculum in Oakland -- in seeming violation of state educational policy -- stems from a lack of funding, the newspaper reported. Oakland schools have seen budgets steadily cut, leaving nonprofits to fill in the holes.

The study also found that LGBT and Asian students are less likely to hear about sex at home, meaning that the schoolroom is the place to learn about sexual practices.